Scaffolding and like structures



Oct, 2a, 1948.

E. o SULLIVAN 2,452,487

SCAFFOLDING AND LIKE STRUCTURES Filed July 9, 1946 4' Sheets-Sheet 1 I l 4/2 J I l L 3/6 1 I \5 l5 a T] 20 Inventor A'UGIEWE O'Juzumy Agent Oct. 26, 1948. E. OSULLIVAN SCAFFOLDING AND LIKE STRUCTURES 4 Sheets-Sheet 3 Filed July 9, 1946 T Oct. 26, 1948. E. OSULLIVAN.

SCAFFOLDING AND LIKE STRUCTURES 4 Sheets-Sheet 4 Filed July 9, 1946 Patented Oct. 26, 1948 ND KE SIBQQF JWS. Eugenev 0;Sul1ivan, Chislehu st, Englgtgml Application Jplyfi, 1946, Serial new ease -1 Th s: n ion m tes S immin dJ ke t t A id p e for use in the construction'o fhquses'ja hd other' buildings, ere also qa geqtgbe df q l isup jgntmg. staging a d; the like the. cqrtstx uetion of. hip a d 'e' h f ldin t uctur o he fint enii i m x e i iw' 'r-.-' v fi ed fpfe t fem; a, fxan ewol k su itable for many other. pup- I vislon of an impmyed scafioldmg qr'llike structure assemmea. al

the inve tioh isfthe provision ot. el 'scelffolding or other structure which oa n b'e built u t i' ehyfisshged size a e height 331 which cambeegq qt s c sion dema e Aeeoxgding to theiq entipn ip, a, seaflol ding 0;: 1 2 lu eie fi e east ur s; eaeh t th ese gptscor grises foupnupi ig'hts, m {I rigidly. eonneeting the said q'pnights togethei; in

pairs to. form twovffiiigect'fnamesl ago at least two. t chapm bqmieetediat thei;

horizonta lirgembets ld nds hfi i mssi orm ra t r it g onebi 'seicl ni n e i te h t-emitte xit o i hier unit with thelip lii ghts. of: the/upper. unit su er; mp sed 'on Wr gh s we qwe u it d means 'bei g pxgov'ilded fox: c9;ii :1'ecti g thfU-LQPFIL. and lower: uprights together to. get e i them P rlefenabl y one, Qf the said units comppis es a psi; of. fixegi end {names and. at least two" Iohgi: l na ei l v a b y m nimiz n h i frames together to form th li lni agholth el of the sztigi quits eor gpises a pah; of fix side flames altigl zit least: two; tr an s vel se memb ezjs detaliably, qq ee iee t e i e memes wsge he t w t s a afi me ils f trueturi i snt is teb T e ts W t ie e lt Whale i any s titgbl e section, and. themeaps for con eetiiig the.

99 wil KQ 1Pr 1 be thn a rtcmeeni ne 'nier' hex; for eat-151 upright ofi'e'eph abqy'e thbase 'unit, means beifig provided for positing-1 mg, the inne z membex; t0v overlap the jb ht hewe t-1 he we??? t ew x lt I m e than wo supelfp e11 ugmts are used th' su e,

being. eaJsyJtO.

2; her below them, the lengths of the members beipg a l e ual t q n hst the q fi ew t pp gmg, H, A .H t The means for detachalqly eq hec tt g the hol izopta l meggaeps to the fixed; fgames preferably cpplsist of so clgets mijizhted on the 'fr'mes and. mapfeq e ieiieiife' pms'pmmegoh the rg' thefmrpb'ers'. "Wh

greater length is required then is firoy ided hy members eoh eet'ing the ei id frames' together, the" resultbeing at cor'itihu'ous scqfi oldifig df a'iiy de si'rea length. Planks or boards are'sjlfifioited the transverse members for the then t'owf'k 'oh;

insuflicient owing t6 the incr giri'g height ofthe wall, '5 secoridunit iserleizted. on t'OpbfE'thefiIfSt the planks being moveddip ohtb'thi's's ec 'd'unitf Psefrabli? the seconct'iinit ishoh'stri ite'd ttith: fixed sideframes' conneotd together" by 'rmoiiab ltransverse members." v

Thqsit will be"seen that the invention;provides a structure which, hile beifig'' $11-37 ass' b eq algal rigi d.

Figure '1 is'a'g'eneral vievy from the front o'f- 'lfor a'b'e'tter understen di ng of-the inventio'n the the removable longitudinal and transverse members or bars are connected to the uprights.

Referring more particularly to: Figures 1 and the section of scaffolding shown comprises a base unit I, four superimposed units 2, 3, 4 and 5 and a hand-rail 6. v

The base unit I comprises two fixed end frames, each consisting of front and rear uprights I and I I' permanently connected together by transverse bars l2 and I3. These bars are connected to the uprights by Welding or other suitable means. Diagonal struts I4 serve to brace the frames and give additional rigidity. Feet l of suitable area to take the weight involved without sinking an excessive amount into the ground are provided on all the uprights. The two end frames are detachably connected together to form a unit by means of removable longitudinal members I6 and H which are fixed to the uprights by means of socket connections which will be more fully described later.

While the uprights are shown as being of circular section they may be of square or any other suitable section if desired.

The second unit 2 consists of two fixed longitudinal or side frames, each consisting of right.

and left hand uprights 2| I] and 2H connected together at their upper ends only by means of a fixed longitudinal bar 2I2 welded in position. Diagonal struts 2I4 may be provided to give strength and rigidity. The two side frames so constructed are secured together on top of the base unit by means of removable transverse members 2I3.

The third unit is similar to the base unit in that it consists of fixed end frames secured together by removable longitudinal members, but in this case there are no lower fixed tranverse bars corresponding to the bars I 3 nor are there lower longitudinal members to correspond to the members II. Each end frame consists of front and rear uprights 3H and 3H connected together by a transverse bar M2 and braced by struts 3. The two end frames are connected together by means of removable longitudinal members 3 I 6.

The fourth unit is similar in every respect to the second unit. It comprises uprights MD and 4| I, which are permanently connected in pairs by longitudinal bars M2 and struts M4 to form 4 fixed side frames. These frames are detachably connected together by transverse members M3.

Similarly, the fifth unit corresponds to the third unit, comprising as it does uprights 5H! and 5| I, fixed transverse bars 5I2 and struts 5| 4 and removable longitudinal members SIG.

The fifth unit is surmounted by a hand-rail 6. This hand-rail is constituted by a frame which may be similar, except for the omission of sockets or other attachments for transverse members, to one of the fixed side frames of units 2 or 4'. Each hand-rail consists of a pair of uprights GIIJ and 6H rigidly connected together by means of a rail M2 and braced by means of struts 6H.

The construction of the uprights and the method of fitting and securing the uprights of an upper unit onthe uprights of a lower unit are most clearly shown in Figure 3, which shows, not to scale, one upright of a base unit on which the tion of these sockets and the purpose of the member 20 mill be more fully described in due course. For the sake of clearness a lower socket I22 and the associated member I! have been omitted from Figure 3.

The foot I5 is attached by welding at H3 to an inner tubular leg member H4. This leg is of a diameter to fit loosely but without excessive play within the tubular upright Ill. The length of the leg H4 is half that of the upright, the top of the leg being indicated at Ill.

When the base unit has been assembled and a second unit is to be erected on it an inner tubular member H5 is inserted into the upper end of the upright I0 until it rests on the end II! of the leg H4. The upper half of the member H5 will project above the top H8 of the upright I0 and on it is fitted the tubular upright 2I0 of the second unit. If a third unit is to be fitted another inner member 2I5, similar to the member H5, is inserted in the upper end of the upright 2H] and serves in to turn to receive the upright 3) (Figures 1 and 2i. 7

Thus the scaffolding can be built up for as many units as are necessary using inner mem bers super-imposed one upon the other within the tubular uprights to provide the connection between successive units. By reason of the staggering of the joints between the inner members with respect to the joints between the outer uprights a firm and rigid structure is obtained. One upright can only be removed from the one below it by raising it axially clear of the inner memher. This cannot happen accidentally when the scaffolding is in position but it can easily be done when the scaffolding is being dismantled.

In order that the scaffolding may be adapted to stand on uneven ground means are provided for adjusting the feet. These means may com- 40 3 lected pair of a series of opposed holes i I6 in the inner leg member I I4. When the scaffolding is being erected any foot which is to stand on lower ground is partly withdrawn, with its attached leg H4, from the upright by the necessary amount and is locked in position by inserting a pin through the holes in the upright and through the appropriate pair of holes H6. This will have the effect of lowering all the superimposed inner members I i5, 2I5, etc, by corresponding amounts, but the joints (between these members will still be staggered with respect to the joints between the uprights.

Figure 4 shows in greater detail a scaifolding structure which is similar to that shown in Figures 1 and 2 except for the fact that the fourth and fifth units have been omitted. Also Figure 4 illustrates how two sections of scaffolding can be connected together to provide an extended length of scaffolding. Furthermore it shows 7 a more clearly the manner in which the fixed transcorresponding upright of the second unit is beverse bars (3, I2, 3| 2, etc., and the fixed longitudinal bars 2I2, BIZ, etc, are fixed to their respective uprights by welding, while the removable members 11, I6, 3I6, etc., are detachably connected to the uprights by means of sockets IZI, etc., welded to the uprights in the appropriate positions.

As is shown in Figure 4 the uprights I0 and Hare, each formed with .onelower socket I22 to receiveamember I1 and with two upper sockets I2I for the members l6 and 20. The construcease-gar tion-and arrangement of, the: sockets I 2 I and I 22.

are-.'more:-c1ear1yshown-in Figures 5 and. 6 re-. spectively.

Theuprights 2.10 andlitof thesecond-unit, in common a with the uprights of other; units having; fixeds-ideframes, areeach provided with a; pairof sockets such as; 22lwhich are arranged at.- right anglestoeach other as shown inFigure 7. thesesockets being adapted to receive a,tra-ns.-v verse member 2l3 and, when necessary adongi tudinal tie, member; such as 236: similar to the, member: 211..

Inthe case; of: the third" and other units hav ing fixed; end frames,- each upright: is provided with a. pair or sockets arrangedina similar: man.-v ner: to the sockets l2lon the base unit and adapted to receive members 3 Iii. 3.2.0; etc.;

E'inallyin therail section each upright 8| i1 and. filt is provided with a singlesocket 621. adapted to receive a tie. rail suchas. 62.0,, whennecessary. An example of such a socket is shown: in- Figure 8;

Every section of scaiiolding consisting of any. desirednumben of units, each comprisingfour uprights connected together, is: complete in itself, While it. would be possible merely to. erect two sections closetogetherendto end when alonger. run of' scaffolding; is required, this is awasteful system when a run of more than twice the length of a section is required. In such cases itisprefer-red: to erect two sections spaced apart by a distanceequaltothelength of, one section. Thesecond of thesesections is indicated inFigure 4- by the uprights Illa, 211a, 3-lilaandby the transverse-bars 130., [2a, etc; The two adjacent; sec-. tions: are connected together by removabletie members Zll, 220. 320, etc. to form a continuous runofscafiolding. Any number of sections maybe added as-required.

Once, the scaffolding structurehas been erected to: the, desired height, boards or planks are laidon: the topmost. series of transverse members; which, may be of larger section than thelongitudinal members in, order to takethe load. For; additional strength one or more additional removable transverse support bars may-be providedrestingon the longitudinal members intermediate the ends of the-latter. Also removably connected; diagonal struts (not shown) may be provided, each connected at one end to a transverse meme her and at the other end to an adjacentlongitudinal mmber.

As shown in Figures t to 8 each socket con.- sists of a short length of channel iron; open atits; upper end. Its lower end may be open or closed. This socket is welded; as at 222 and 223, to the upright and to any adjacent socket. Each socket is formed-inits upper lip with a cut-out. or recess such. as 2-24, (Figure 7-) of aheight and; width corresponding to the cross-section of the traces verse member. which is to be connected to the socket.

Each. detachable transverse or longitudinal member, such as 213 (Figure 7-) consists of: a length of channel iron to each end of which is welded a vertical pin 225- which is adapted to fitin the appropriate socket 22!. Theend. of the member 2L3 enters the recess 2 24, the member thus being securely connected to, the: upright 2 M from which, however, it may bereadily and quickly disengaged when required.

In. certain cases it may be desired to. arrange two or more sections of scaffolding side by side and. to. connect them together by removable tie members similar to the members 29. 226;, etc.

To enable this to be donev each; uprightmaybe nrovidedwith an additional socket (not shown) on-itsfrontface in the case of a. front upright such as H] or onits back face-in the case of arback uprig ht such-as. H. This will enableany. number of sections to be assembled and; corn nected together'in any of a Wide variety of ways tosuit different purposes.

It may, in certain cases, be desired to extend the; height of the scaffolding, or,- or one or more units thereohwithout the inclusion of-additional horizontal bars or members. For example; it may be-required toprovideaseries-of gstages of: a height; greater than that of theindividualunits, eachstage beingunimpeded by such an obstruction. as would be provided by anintermediate horizontal member.

provided which are adapted to be interposed j be.- tweenthe, tops of; theuprights. of, one unit. and thebottoms of. the uprights of the next unit.

Additional. inner member may be provided: to

constitute the connections. between theaddi-v t-ionaluprights. and the uprights ofthe -superposed units. Furthermore; for additional rigidity, external sleeves may be provided adapted-to; over- Iapthese connections. Each sleeve may. be located onthe-upright by-means of a, studmountedon,the upright and engaging in a longitudinalslot cutin the-sleeve.

The'dimensions of the'units of the scafiolding may be selected to suit particular requirements. For; scaffolding to beused in building a length of ninefeet anda width of four feet are convenient.

' A. suitable height for the base unit isthree; or

four feet while all succeeding units may 'ha ea standardised height of fourfeet. The invention is not limited to any particular dimensions, how;-v ever, since these may be varied asr-eguired.

Furthermore, the invention is not limited to the. particular construction described and shown. Various modifications. may be made without departing from the scope of the invention as set forthin the appended claims.

I claim:

1'. A. scaiiold structure including least. two units, one ofwhich units comprises four up.-. right-s, means rigidly connecting said, uprights together inipairs toform two end frames, at least two. longitudinal members and means for de-. tachably connecting said longitudinalmembers at1thei-r ends to said end frames to form the unit, and another. of which units comprises four uprights, means rigidly connecting said uprights together in pairs toform two side frames, at least two transverse members and means for detachably connecting said transverse members at their ends tosaid side frames to form the unit, one of said units being adapted to be erected; on

top of, the other said unit with the uprights of" the upper unit superimposed on the uprights of the lower unit and means being provided forconnecting the corresponding uprights or the upper and. lower unit together to retain them againstlateral. displacement. 1

2. A scaffold structure including at least two units, one of" which units comprises four; uprights, means rig-idly connecting said; uprights together in-pairs-to form two end frames, at least two; longitudinalmembers and; means for detachably connecting said longitudinal members attheir ends tosaid end frames to form the unit, and another of which units comprises, fQ lr uprights, means rigidly connecting said uprights og ther n. pa rs to rm w si rames he To enable this. to be, doneadditional individual tubular uprights may be length of said side frames being greater than the length of said end frames, at least two transverse members and means for detachably connecting said transverse members at their ends to said side frames to form the unit, one of said units being adapted to be erected on top of the other said unit with the uprights of the upper unit superimposed on the uprights of the lower unit and means being provided for connecting the corresponding uprights of the upper and lower units together to retain them against lateral displacement.

3. A scafiold structure including at least two units, one of which units comprises four tubular uprights, means rigidly connecting said uprights together in pairs to form two end frames, at least two longitudinal members and means for detachably connecting said longitudinal members to the said end frames to form the unit, and another of which units comprises four tubular uprights, means rigidly connecting said uprights together in pairs to form two side frames, at least two transverse members and means for detachably connecting said transverse members to said side frames to form the unit, one of said units being adapted to be erected on top of the other said unit with the uprights of the upper unit superimposed on the uprights of the lower unit, for each upright of the lowermost unit an inner member freely fitting within the upright, means for positioning said member within the upright with its upper end below the upper end of the upright, and for each upright of each superimposed unit an inner member which is freely slidable within said upright and within the upper part of the next lower upright, which inner member is supported by its lower end resting directly on the upper end of the said inner member within the next lower upright.

4, A scaffold structure including at least two units, one of which units comprises four tubular uprights, means rigidly connecting said uprights together in pairs to form two end frames, at least two longitudinal members and means for detachably connecting said longitudinal members to the said end frames to form the unit, and another of which units comprises four tubular uprights, means rigidly connecting said uprights together in pairs to form two side frames, at least two transverse members and means for detachably connecting said transverse members to said side frames to form' the unit, one of said units being adapted to be erected on top of the other said unit with the uprights of the upper unit superimposed on the uprights of the lower unit, for each upright of the lowermost unit an inner member freely fitting within the upright, a foot mounted on the lower end of said inner member, means for adjustably positioning said member within the upright with its upper end below the upper end of the upright, and for each upright -of each superimposed unit an inner member which is freely slidable within said upright and within the upper part of the next lower upright, which inner member is supported by its lower end resting directly on the upper end of the said inner member within the next lower upright.

5. A scaffold structure including at least two units, one of which units comprises four uprights, means including a horizontal bar secured at its ends to the tops of two of said uprights to form a rigid end frame, means including a horizontal bar secured at its ends to the tops of the other two of said uprights to form a second rigid end frame, a pair of longitudinal members and means for detachably connecting said longitudinal members at their ends to the tops of the said end frames to form the unit, and another of which units comprises four uprights, means including a horizontal bar secured at its ends to the tops of two of said uprights to form a rigid side frame, means including a horizontal bar secured at its ends to the tops of the other two of said uprights to form a second rigid side frame, the lengths of said side frames being greater than the lengths of said end frames, at least two transverse members and means for detachably connecting said transverse members at their ends to the tops of said side frames to form the units, one of said units being adapted to be erected on top of the other said unit with the uprights of the upper unit superimposed on the uprights of the lower unit and means being provided for connecting the corresponding uprights of the upper and lower units together to retain them against lateral displacement.

6. A scaffold structure including at least two units, one of which units comprises four tubular uprights, means including a horizontal bar secured at its ends to the tops of two of said uprights to form a rigid end frame, means including a horizontal bar secured at its ends to the tops of the other two of said uprights to form a second rigid end frame, a pair of longitudinal members and means for detachably connecting said longitudinal members at their ends to the tops of the said end frames to form the unit, and another of which units comprises four tubular uprights, means including a horizontal bar secured at its ends to the tops of two of said uprights to form a rigid side frame, means including a horizontal bar secured at its ends to the tops of the other two of'said uprights to form a second rigid side frame, at least two transverse members and means for detachably connecting said transverse members at their ends to the tops of said side frames to form the unit, one of said units being adapted to be erected on top of the other said unit with the uprights of the upper unit superimposed on the uprights of the lower unit, for each upright of the lowermost unit an inner member freely fitting within the upright, means for positioning said member within the upright with its upper end below the upper end of the upright, and for each upright of each superimposed unit an inner member which is freely slidable within said upright and within the upper part of the next lower upright, which inner member is supported'by its lower end resting directly on the upper end of the said inner member within the next lower upright.

7. A scaffold structure including a plurality of units, each of which units comprises four tubular uprights, means rigidly connecting said uprights together in pairs to form two frames and a plurality of members for connecting said frames together to form the unit, means being provided for detachably connecting said members with said frames, the said units being adapted to be erected in superimposed relationship with the corresponding uprights superimposed directly one on the other, for each upright of each unit above the lowermost unit an inner member freely slidable in the upright, the length of said inner member being substantially equal to the length of said upright and means within each upright of the lowermost unit for supporting the corresponding inner member of the next superimposed unit, the inner members of any units above the said next unit being supported with their lower ends resteasants? "ingidirect-ly bnk'the inner member of the t'next lower unit.

"8. *A scaffold "structure including "a "base .unit

and at least 'oneupp er"unit' adapted-"toibe erecteli means rig-idly connecting said=-upiights-=together "in "pairs to form frames, means -for detachably connecti-ngsaid frames togetherto formthe -nriit, and a-n inner -member freely slidable within each upright, the length -of 'eaches aid inner i member being substantiallyequalqto thellength of the corresponding upright, and one upper unit being adapted to be erected on topofthe base un-it'with the uprights of saidupper -un'it suppo'rted'directly on the upper ends of the uprights of the base unit and with the inner members of said upper unit supported directly on the inner legs of the base unit.

9. A scaffold structure including at least two units, each of which units comprises four uprights, means rigidly connecting said uprights together in pairs to form two frames, a plurality of connecting members and means for detachably connecting each of said connecting members at each end to one of said frames, thereby to conmeet the frames together to form the unit, said means comprising a tubular socket mounted on the frame and a downwardly extending pin mounted on the member at the end thereof, said socket being open at its upper end to receive the pin and being formed with a slot which extends part way down from its upper end, said slot being adapted to receive the end part of said member, which end part rests on and is supported by the bottom of the slot.

10. A scaffold structure including at least two units, one of which units comprises four uprights, means rigidly connecting said uprights together in pairs to form two end frames, at least two longitudinal members and means for detachably connecting said longitudinal members at their ends to said end frames to form the unit,

said means comprising a tubular socket mounted on the frame and a downwardly extending pin mounted on the member at the end thereof, said socket being open at its upper end to receive the pin and being formed with a slot which extends part way down from its upper end, said slot being adapted to receive the end part of said member, which end part rests on and is supported by the bottom of the slot, and another of which units comprises four upright, means rigidly connecting said uprights together in pairs to form two side frames, at least two transverse members and means for detachably connecting said transverse members at their ends to said side frames to form the unit, said means comprising a tubular socket mounted on the frame and a downwardly extending pin mounted on the member at the end thereof, said socket being open at its upper end to receive the pin and being formed with a slot which extends part way down from its upper end, said slot being adapted to receive the end part of said member, which end part rests on and is supported by the bottom of the slot, one of said units being adapted to be no erected on top "of f the other said unit with the uprights of the "upper unit superimposed on the uprights "of the lower unit =and mean's' being'pro- =v'iiiedfor connecting; the corresponding uprights e the upper and lower 1 units I together -to *retalin *them-against lateral-displacement.

1. A -scafffold structure i including a't =-least two "units; one-=01 which units'comprises four tubular uprights} means rigidly connecting-said-uprights togetherin 'pairs to' 'fornr-two end frames, at ileast two longitu'dinal members and -means ror ldeitachably "connecting "said longitudinal members i; the said end frames to form the unit, saiu i'm'ean's comprising a tubularsooket' mounted on 0 the f-rame and a -uo'wnwardly extending pin *mounted'on the member' at the=end-thereo f, said socket being open at -its upper -=erid to receive th'e pin and being formed with-a slot which extendspartway down-from its upperendsaid slot *being adapted to receive the end *part --of safd *m'em-ben which end part rests on an'd is =supported by the bottomofthe-slot, and another of which 'iunits -comprises four' tubular uptig'hts, means rigidly connecting said uprightstogether in pairs to form two side frames, at least two transverse members and means for detachably connecting said transverse members to said side frames to form the unit, said means comprising a. tubular socket mounted on the frame and a downwardly extending pin mounted on the member at ,the end thereof, said socket being open at its upper end to receive the pin and being formed with a slot which extends part way down from its upper end, said slot being adapted to receive the end part of said member, which end part rests on and is supported by the bottom of the slot, one of said units being adapted to be erected on top of the other said unit with the uprights of the upper unit superimposed on the uprights of the lower unit, for each upright of the lowermost unit an inner member freely fitting within the upright, means for positioning said member within the upright with its upper end below the upper end of the upright, and for each upright of each superimposed unit an inner member which is freely slidable within said upright and within the upper part of the next lower upright, which inner member is supported by its lower end resting directly on the upper end of the said inner member within the next lower upright.

12. A scaffold structure including at least two units, one of which units comprises four tubular uprights, means including a horizontal bar secured at its ends to the tops of two of said uprights to form a rigid end frame, means including a horizontal bar secured at its ends to the tops of the other two of said uprights to form a second rigid end frame, a pair of longitudinal members and means for detachably connecting said longitudinal members at their ends to the tops of the said end frames to form the unit, said means comprising a tubular socket mounted on each said upright adjacent the upper end thereof and a downwardly extending pin mounted on each said member at the end thereof, said socket being open at its upper end to receive the pin and being formed with a slot which extends part way down from its upper end, said slot being adapted to receive the end part of said member, which end part rests on and is supported by the bottom of the slot, and another of which units comprises four tubular uprights, means including a horizontal bar secured at its ends to the tops of two of said uprights to form a rigid side frame, means including, a horizontal bar secured atits ends to the tops of the other-two .ofsaid uprights to form a second rigid side frame,

,a. ;pair of transverse members and meansrfor detachabl'y connecting said transverse members at their ends to the tops of said side-frames to form the unit, said means comprising atubular socket mounted on each said upright adjacent the upper end thereof and a downwardly extendgin pinmounted on each said member at theend thereof, said socket being open atits upper end to receive the pin and being formed with a slot :which extends part way down from its upper ;end, said siot being adapted to receivethe end part ofsaid member, which end partrests on :andis-supported by the bottom of the slot, one

of said units being adapted tobe erected on top of theother said unit with the uprightsof the upper; unit superimposed-on the uprights of the lower unit, for each upright of the lowermost unit an inner member-freely fitting within the uprig-ht,gmeans for positioning said member within the upright with its upper end below-the upper end of the upright, and for each upright of each 12 superimposed unit an inner member which is freely slidable within said upright and within the upper part-of the next lower upright, which inner member is supported by its lower end rest-- ing directiy on the upper end of the said inner member within the next lower upright.

' EUGENE OSULLIVAN.

REFERENCES CITED The following references are of record in file of this patent:

UNITED STATES PATENTS the Number 

